I see there are 30 and 40 amp ones, how do i even tell which generator i have? Or does it matter?

I lost all charging on the way home. It came on once with a high rev and the light stayed off all the way home but the next time i fired it up it stayed on nomatter what. I still havent throw a volt meter on the generator but i'm making the easy guess.

Oh and ive heard a rumor that the new regulators dont require polarizing?